OTTAWA - A federal judge has struck down a national security certificate against a Syrian-born man arrested eight years ago on terror suspicions.

The ruling Monday by Federal Court Justice Richard Mosley effectively frees Hassan Almrei and delivers the latest in a series of blows to the security-certificate law.

Almrei spent seven years in jail before moving to a Mississauga, Ont., townhouse last February under strict release conditions, including an electronic tracking ankle bracelet.

The government had been trying to deport Almrei on a security certificate - a seldom-used provision of the immigration law for removing suspected terrorists and spies.

The federal government has launched a sweeping review of the certificate system after acknowledging the teetering process needs fixing.

Mosley's ruling says there were reasonable grounds to believe Almrei was a security danger when detained in October 2001 following terrorist attacks on the United States, but there are no longer grounds to uphold that belief today.

The judge chastised the Canadian Security Intelligence Service for presenting an outdated view to the court "without considering whether the state of knowledge about the risks to national security posed by Islamic extremists had evolved" since Almrei was arrested.

The government had argued the Syrian native's travel, activities and involvement in a false-document ring were consistent with supporters of Osama bin Laden's al-Qaida network.

The judge said Almrei had undergone a transformation for the better since his days as an opportunist willing to peddle forged documents.

Almrei's lawyer, Lorne Waldman, said his client was "very excited" over the ruling.

Waldman said Mosley delivered a complete vindication.

"He goes through all the different allegations that the government has made against Mr. Almrei and rejects all of them one by one. It's quite incredible."

Waldman noted that if the judge allows the government to challenge the ruling, by formally certifying a question of law in the case, then the matter goes to the Federal Court of Appeal. Without a formal certification, "it's final, it's over."

Mosley said he would give both sides more time to put forward arguments on that matter.

His ruling says CSIS and federal cabinet ministers breached their duties of "good faith and candour" to the court by not thoroughly reviewing the information on file prior to re-issuing the certificate against Almrei in February of last year.

The federal review of the security certificate system could see an overhaul or retirement of the law used to arrest and deport non-Canadians considered a threat to national security.

Certificates have existed for three decades, and more than two dozen have been issued since 1991, when they became part of federal immigration law.

But recent cases have slowed to a crawl - or collapsed altogether - amid legal challenges and upbraidings from judges over miscues by Canada's spy agency.

The government has initiated just six certificate cases - four terror suspects, a hate monger and an alleged Russian spy - since the 9-11 attacks on the United States.

Public Safety Minister Peter Van Loan said there are a number of reasons for reconsidering the security-certificate system.

"An increasingly complex legal environment, and the significant costs associated with outstanding certificates, are factors in the current review," he said.

"Our review is focused on the challenge of how to protect Canadians' security while recognizing the obstacles emerging under the existing security certificate regime."

Among critics, the deportation tool has come to symbolize the worst aspects of the fight against Islamic extremism.

Opponents say the process is fundamentally unfair because detainees are not given full details of the allegations against them.

A case involving Montrealer Adil Charkaoui, a native of Morocco, fell apart recently when the government withdrew supporting evidence, saying its disclosure would reveal sensitive intelligence sources and methods of the Canadian Security Intelligence Service.

Waldman said that's the key difference between Charkaoui and Almrei; in Almrei, all the evidence was heard.

"In this case all of the government's case went in . . . the court still rejected their case."

Charkaoui, a French teacher and father of three, wants compensation for his six-year ordeal.

Four active cases range from seven to 10 years old, illustrating the legal limbo that certificates can create for detainees.

Mahmoud Jaballah and Mohamed Zeki Mahjoub, both Egyptian, were arrested in 1999 and 2000 respectively, while Almrei was detained one month after Sept. 11, 2001, and Mohamed Harkat of Algeria seven years ago this month.

All four men were granted release from prison under strict conditions that have controlled virtually their every move while the cases play out in the Federal Court of Canada.

Waldman said these cases could be troublesome for the security service, which was the driving force behind them.